Integrated chip inductor structure

ABSTRACT

The present disclosure relates to, in part, an inductor structure that includes an etch stop layer arranged over an interconnect structure overlying a substrate. A magnetic structure includes a plurality of stacked layers is arranged over the etch stop layer. The magnetic structure includes a bottommost layer that is wider than a topmost layer. A first conductive wire and a second conductive wire extend in parallel over the magnetic structure. The magnetic structure is configured to modify magnetic fields generated by the first and second conductive wires. A pattern enhancement layer is arranged between the bottommost layer of the magnetic structure and the etch stop layer. The pattern enhancement layer has a first thickness, and the bottommost layer of the magnetic structure has a second thickness that is less than the first thickness.

BACKGROUND

An integrated circuit (IC) is an assembly of electronic components on apiece of semiconductor material. A widely used electronic component inan IC is an inductor. An inductor is a passive element that storeselectrical energy in a magnetic field when electric current flowsthrough the inductor. Inductors are versatile devices that may be usedin, among other things, resistor-inductor (RL) filters,inductor-capacitor (LC) circuits, resistor-inductor-capacitor (RLC)circuits, power supplies, transformers, and many other circuitcomponents.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIGS. 1A-1B illustrate cross-sectional views of some embodiments of aninductor structure having a first pattern enhancement layer between afirst etch stop layer and a first magnetic shielding structure.

FIGS. 2-4 illustrate cross-sectional views of some additionalembodiments of a first pattern enhancement layer between a first etchstop layer and a first magnetic shielding structure.

FIG. 5 illustrates a cross-sectional view of some additional embodimentsof an inductor structure having a first pattern enhancement layerbetween a first etch stop layer and a first magnetic shielding structureand having a second pattern enhancement layer between a second etch stoplayer and a second magnetic shielding structure.

FIG. 6 illustrates a cross-sectional view of some additional embodimentsof an inductor structure having a first pattern enhancement layer belowa first magnetic shielding structure, and a second magnetic shieldingstructure having a center portion recessed below topmost portions of thesecond magnetic shielding structure.

FIG. 7 illustrates a cross-sectional view of some additional embodimentsof an inductor structure having a second pattern enhancement layerbetween a second magnetic shielding structure and a second etch stoplayer, wherein the second pattern enhancement layer has a center portionrecessed below topmost portions of the second pattern enhancement layer.

FIGS. 8A and 8B illustrate various views of some embodiments of aninductor structure having a first pattern enhancement layer and coupledto an interconnect structure by contact vias.

FIGS. 9-20 illustrate cross-sectional views of some embodiments of amethod of forming an inductor structure having a first patternenhancement layer between a first etch stop layer and a first magneticshielding structure.

FIG. 21 illustrates a flow diagram of some embodiments of the methodillustrated in FIGS. 9-20 .

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Inductors having useful inductances often consume a large area on anintegrated circuit. Therefore, to avoid occupying valuable space,inductor structures may be formed over an interconnect structure over asemiconductor substrate. Such inductor structures, in some embodiments,comprise an etch stop layer overlying a passivation layer on theinterconnect structure. A magnetic structure is disposed over the etchstop layer. A first conductive wire and a second conductive wire extendin parallel with one another along an upper surface of the magneticstructure. A dielectric structure may overlie the first and secondconductive wires, as well as the magnetic structure, such that the firstand second conductive wires are spaced apart from one another andcovered by the dielectric structure.

During operation, the first and second conductive wires may each becoupled to control circuitry configured to apply a first current to thefirst conductive wire in a first direction and a second current to thesecond conductive wire in a second direction. Because of the “right-handrule,” first and second magnetic fields may be induced around the firstand second conductive wires, respectively, and give the inductorstructure a measureable inductance. In some embodiments, the magneticstructure is configured to concentrate the first and second magneticfields near the first and second conductive wires and away from anunderlying interconnect structure.

In some embodiments, the magnetic structure may be formed by depositinga tantalum layer over an etch stop layer, depositing a cobalt zinctantalum (CZT) layer over the tantalum layer, and further depositing anoxygen-CZT (OCZT) layer over the CZT layer. A first wet etching processmay be used to remove peripheral portions of these layers according to amasking layer. However, during the first wet etching process residuefrom the OCZT layer may be produced and stick to the etch stop layerbecause the OCZT layer has a slower etch rate than the CZT layer and thetantalum layers. In some embodiments, the OCZT residue may be detectedas cobalt oxygen (CoO) precipitates through chemical analysis, such asenergy dispersive X-ray spectroscopy (EDX) analysis. A dry etchingprocess may be subsequently performed to remove peripheral portions ofthe etch stop layer, but at least some of the OCZT residue (e.g., CoOprecipitates) and underlying etch stop layer remains because the OCZTresidue may be resistant to the dry etching process. The OCZT residuemay negatively impact the effectiveness of the magnetic structure andcause leakage of the first and second magnetic fields.

Various embodiments of the present disclosure present an inductorstructure comprising a first pattern enhancement layer between amagnetic structure and the first etch stop layer. The magnetic structuremay comprise several groups of layers, respectively comprising atantalum layer, a CZT layer arranged over the tantalum layer, and anoxygen-CZT (OCZT) layer arranged over the CZT layer. The first patternenhancement layer may be thicker than a lowermost layer of the magneticstructure, and provide more space and time for the OCZT residue to getremoved during the patterning of the magnetic structure. For example,during the first wet etching process, OCZT residue (e.g., CoOprecipitates) is produced as a topmost OCZT layer is exposed to thefirst wet etching process. By the time a bottommost OCZT layer isexposed to the first wet etching process, the OCZT residue from thetopmost OCZT layer is almost completely or completely removed, but OCZTresidue from the bottommost OCZT layer is produced. In order for theOCZT residue from the bottommost OCZT layer to be removed and to preventthe OCZT residue from contacting the first etch stop layer, the firstpattern enhancement layer provides another barrier between the OCZTresidue and the first etch stop layer. Thus, by the time the firstpattern enhancement layer is removed from the first etch stop layer, theOCZT residue has been completely removed. Therefore, the first patternenhancement layer and the first wet etching process may effectivelyremove OCZT residue before the OCZT residue contacts the first etch stoplayer such that the inductor structure can reliably concentrate firstand second magnetic fields induced by the first and second conductivewires, respectively.

FIG. 1A illustrates a cross-sectional view 100A of some embodiments ofan inductor structure comprising a first pattern enhancement layer.

The inductor structure in the cross-sectional view 100A includes a firstpassivation layer 102 and a first barrier layer 104 arranged over aninterconnect structure 140. In some embodiments, the interconnectstructure 140 comprises a network of interconnect wires 142 andinterconnect vias 144 embedded in an interconnect dielectric structure146. In some embodiments, the interconnect structure 140 is arrangedover a substrate 128 and coupled to semiconductor devices 130. In someembodiments, the semiconductor devices 130 may be, for example, metaloxide semiconductor field-effect transistors (MOSFETs) comprisingsource/drain regions 130 a within the substrate 128 and a gate electrode130 b over the substrate 128. The gate electrode 130 b may be separatedfrom the substrate 128 by a gate dielectric layer 130 c. Thesemiconductor devices 130 and the interconnect structure 140 may becoupled to a first conductive wire 114 and/or a second conductive wire116 to operate the inductor structure.

The first and second conductive wires 114, 116 are arranged over a firstmagnetic structure 110, and the first magnetic structure 110 may bearranged over a first etch stop layer 106. In some embodiments, a firstpattern enhancement layer 108 may be arranged between the first etchstop layer 106 and the first magnetic structure 110. The first patternenhancement layer 108, in some embodiments, may directly underlie thefirst magnetic structure 110 and may be narrower than a bottommostsurface of the first magnetic structure 110. Thus, the first patternenhancement layer 108 may have been laterally etched more or faster thanthe first magnetic structure 110. The first pattern enhancement layer108 may comprise a material that can be dissolved in a same wet etchantas the first magnetic structure 110. For example, in some embodiments,the wet etchant may comprise a mixture of nitric acid and hydrofluoricacid, and the first pattern enhancement layer 108 may comprise tantalum,silicon nitride, titanium, tungsten, zirconium, nickel, silicongermanium, tin, niobium, vanadium, or indium antimony.

In some embodiments, a second barrier layer 112 isolates the first andsecond conductive wires 114, 116 from the first magnetic structure 110.Further, a dielectric structure 118 may overlie the first and secondconductive wires 114, 116, as well as the first magnetic structure 110,such that the first and second conductive wires 114, 116 are spacedapart from one another and covered by the dielectric structure 118. Insome embodiments, the dielectric structure 118 may have a substantiallyplanar top surface. A first isolation layer 120 overlies the dielectricstructure 118 and the first magnetic structure 110. A third barrierlayer 122 may overlie the first isolation layer 120 and laterallysurround the first magnetic structure 110 and the first patternenhancement layer 108. A second etch stop layer 124 may overlie thethird barrier layer 122, and a second magnetic structure 126 may overliethe second etch stop layer 124.

During operation of the inductor structure, a first current may beapplied to the first conductive wire 114, and a second current may beapplied to the second conductive wire 116 by the semiconductor devices130, for example. First and second magnetic fields may be induced aroundthe first and second conductive wires 114, 116, respectively. The firstand second magnetic structures 110, 126 may shield the first and secondmagnetic fields to concentrate a magnetic flux of the inductor structurenear the first and second conductive wires 114, 116.

The first pattern enhancement layer 108 is configured to delay exposureof the first etch stop layer 106 during an etching process used topattern the first magnetic structure 110. By delaying exposure of thefirst etch stop layer 106, the etching process has time to removeresidue from the first magnetic structure 110 before exposing the firstetch stop layer 106, thereby preventing a buildup of residue from thefirst magnetic structure 110 onto the first etch stop layer 106. Bypreventing a buildup of residue from the first magnetic structure 110onto the first etch stop layer 106, the reliability of the firstmagnetic structure 110 in concentrating the magnetic flux to near thefirst and second conductive wires 114, 116 is increased duringoperation.

FIG. 1B illustrates a cross-sectional view 100B that may correspond tosome embodiments of the first magnetic structure 110 and the firstpattern enhancement layer 108 in box A of the cross-sectional view 100Aof FIG. 1A.

In some embodiments, the first magnetic structure 110 may comprise afirst group of layers 110 a and a second group of layers 110 b. In someembodiments, the first group of layers 110 a and/or second group oflayers 110 b comprise a tantalum layer 162, a cobalt zinc tantalum (CZT)layer 164 arranged over the tantalum layer 162, and an oxygen-CZT (OCZT)layer 166 arranged over the CZT layer 164. In some embodiments, thefirst magnetic structure 110 may have an overall trapezoidal-like shape.In some embodiments, a lowermost layer 110L (e.g., a bottommost one ofthe tantalum layer 162) of the first magnetic structure 110 is widerthan a topmost layer 110 t (e.g., a topmost one of the OCZT layer 166)of the first magnetic structure 110.

The first pattern enhancement layer 108 may be arranged between thetantalum layer 162 and the first etch stop layer 106. The tantalum layer162 that directly contacts the first pattern enhancement layer 108 doesnot extend below a top surface of the first pattern enhancement layer108. In some embodiments, the first pattern enhancement layer 108 has afirst thickness t₁ that is in a range of between, approximately 300angstroms and approximately 1000 angstroms. In some embodiments, thetantalum layer 162 that directly contacts the first pattern enhancementlayer 108 may have a second thickness t₂ that is in a range of between,for example, approximately 15 angstroms and approximately 50 angstroms.Thus, the first thickness t₁ may be greater than the second thicknesst₂. The first pattern enhancement layer 108 may be thicker than thetantalum layer 162 in order to provide more time for OCZT residue to beremoved during a first wet etching process before the first etch stoplayer 106 is exposed (see, FIGS. 11A-G).

In some embodiments, the first pattern enhancement layer 108 may haveoutermost sidewalls that are curved from the cross-sectional view 100B.

Further, the first etch stop layer 106 has a first width w₁; thelowermost layer 110L of the first magnetic structure 110 has a bottomsurface that has a second width w₂; the first pattern enhancement layer108 has a bottom surface that has a third width w₃; and the firstpattern enhancement layer 108 has a top surface that has a fourth widthw₄. In some embodiments, the first width w₁ is greater than the second,third, and fourth widths w₂, w₃, w₄. Further, in some embodiments, thesecond width w₂ is greater than the third width w₃. In some embodiments,the second width w₂ is also greater than the fourth width w₄. The secondwidth w₂ is greater than the third width w₃ and/or fourth width w₄because in some embodiments, the first pattern enhancement layer 108 hasa higher etch rate than the tantalum layer 162, such that the firstpattern enhancement layer 108 does not significantly increase the timeof a first wet etching process and reduce manufacturing efficiency.

FIG. 2 illustrates a cross-sectional view 200 of an alternativeembodiment of FIG. 1B, wherein the second width w₂ of the bottom surfaceof the lowermost layer 110L of the first magnetic structure 110 is aboutequal to the fourth width w₄ of the top surface of the first patternenhancement layer 108. In such embodiments, the first patternenhancement layer 108 and the lowermost layer 110L of the first magneticstructure 110 may have about equal etch rates. In such embodiments,because the first pattern enhancement layer 108 does not have a higheretch rate than the lowermost layer 110L (a bottom one of the tantalumlayers 162) of the first magnetic structure 110, there is more timeduring the first wet etching process to remove OCZT residue before thefirst etch stop layer 106 is exposed upon the first pattern enhancementlayer's 108 removal.

FIG. 3 illustrates a cross-sectional view 300 of another alternativeembodiment of FIG. 1B, wherein the first pattern enhancement layer 108and the tantalum layer 162 both comprise tantalum.

In such embodiments, the lowermost layer 110L of the first magneticstructure 110 may appear to comprise the tantalum layer 162 and thefirst pattern enhancement layer 108 because a first interface 302between the tantalum layer 162 and the first pattern enhancement layer108 may not be visible, as illustrated by a dotted line. In suchembodiments, the presence of the first pattern enhancement layer 108 maybe identified by the lowermost layer 110L of the first magneticstructure 110 having a third thickness t₃, which may be a maximumthickness of the lowermost layer 110L. The third thickness t₃ may begreater than the second thickness t₂ of an upper tantalum layer 304. Theupper tantalum layer 304 is above the lowermost layer 110L of the firstmagnetic structure 110.

Further, in some embodiments, the first magnetic structure 110 and/orthe first pattern enhancement layer 108 may have outermost sidewallsthat are substantially planar.

FIG. 4 illustrates a cross-sectional view 400 of yet another alternativeembodiment of FIG. 1B, wherein the first pattern enhancement layer 108is wider than the first magnetic structure 110.

In some embodiments, the first pattern enhancement layer 108 may have aslower etch rate than the lowermost layer 110L of the first magneticstructure 110 to increase the time to remove OCZT residue (e.g., CoOprecipitates) during the first wet etching process before the first etchstop layer 106 is exposed. In such embodiments, third and fourth widthsw₃, w₄ of the first pattern enhancement layer 108 may be larger than thesecond width w₂ of the lowermost layer 110L of the first magneticstructure 110.

FIG. 5 illustrates a cross-sectional view 500 of some embodiments of aninductor structure having a first pattern enhancement layer and a secondpattern enhancement layer.

In some embodiments, an inductor structure also has a second patternenhancement layer 508 arranged between the second magnetic structure 126and the second etch stop layer 124. In some embodiments, the secondpattern enhancement layer 508 may have outermost sidewalls 508 s thatdirectly underlie the second magnetic structure 126. In otherembodiments (not shown), the second pattern enhancement layer 508 mayhave outermost sidewalls 508 s that do not directly underlie the secondmagnetic structure 126. The second pattern enhancement layer 508 mayprevent residue from the second magnetic structure 126 from contactingand sticking to the second etch stop layer 124 during a third wetetching process to pattern the second magnetic structure 126.

In some embodiments, the second magnetic structure 126 may comprise adifferent structure than the first magnetic structure 110. For example,in some embodiments, the second magnetic structure 126 may comprise, forexample, three groups of layers (110 a, 110 b, 110 c of FIG. 20 ),whereas the first magnetic structure 110 may comprise, for example, twogroups of layers (110 a, 110 b of FIG. 1B). In other embodiments, thefirst and second magnetic structures 110, 126 may comprise differentmaterials than one another. Thus, in some embodiments, the first patternenhancement layer 108 and the second pattern enhancement layer 508 maycomprise different materials and/or have different thicknesses. In otherembodiments, it will be appreciated that the first pattern enhancementlayer 108 and the second pattern enhancement layer 508 may comprise asame material and/or have about the same thickness.

FIG. 6 illustrates a cross-sectional view 600 of some alternativeembodiments of the inductor structure as shown in the cross-sectionalview 100A of FIG. 1A.

In some embodiments, the dielectric structure 118 may have an uppersurface. A center portion 118 c of the upper surface is recessed belowtopmost portions 118 t of the upper surface of the dielectric structure118. The topmost portions 118 t of the upper surface of the dielectricstructure 118 may overlie the first and second conductive wires 114,116, and the center portion 118 c of the upper surface of the dielectricstructure 118 may overlie the space between the first and secondconductive wires 114, 116. As a result, the first isolation layer 120,the third barrier layer 122, the second etch stop layer 124, and thesecond magnetic structure 126 may also have upper surfaces with a centerportion recessed below topmost portions. For example, in someembodiments, the second magnetic structure 126 may have an upper surfacethat has a center portion 126 c recessed below topmost portions 126 t ofthe upper surface of the second magnetic structure 126. Thus, in someembodiments, the center portion 126 c of the upper surface of the secondmagnetic structure 126 may directly overlie the center portion 118 c ofthe upper surface of the dielectric structure 118. Similarly, in someembodiments, the topmost portions 126 t of the upper surface of thesecond magnetic structure 126 may directly overlie the topmost portions118 t of the upper surface of the dielectric structure 118.

FIG. 7 illustrates a cross-sectional view 700 of some alternativeembodiments of the inductor structure as shown in the cross-sectionalview 500 of FIG. 5 .

As shown in cross-sectional view 700, the dielectric structure 118 mayhave an upper surface with a center portion 118 c that is recessed belowtopmost portions 118 t of the upper surface of the dielectric structure118. In some embodiments, a second pattern enhancement layer 508 may bearranged between the second magnetic structure 126 and the second etchstop layer 124. Thus, in some embodiments, the second patternenhancement layer 508 may have an upper surface, wherein a centerportion 508 c of the upper surface of the second pattern enhancementlayer 508 is recessed below topmost portions 508 t of the upper surfaceof the second pattern enhancement layer 508. In such embodiments, thecenter portion 508 c of the upper surface of the second patternenhancement layer 508 may directly overlie the center portion 118 c ofthe upper surface of the dielectric structure 118, and the topmostportions 508 t of the upper surface of the second pattern enhancementlayer 508 may directly overlie the topmost portions 118 t of the uppersurface of the dielectric structure 118.

FIG. 8A illustrates a top-view 800A of some embodiments of an inductorstructure, wherein the first and second conductive wires are coupled tocontact vias.

In some embodiments, from the top-view 800A, the first and secondconductive wires 114, 116 are not visible, and thus, are representedwith dotted lines in FIG. 8A. In some embodiments, the first and secondconductive wires 114, 116 are partially covered by the second magneticstructure 126. Under the second magnetic structure 126, the first andsecond conductive wires 114, 116 may extend parallel to one another.Further, an interconnect passivation layer 802 may overlie theinterconnect structure (140 of FIG. 1A), in some embodiments. Portionsof the first and second conductive wires 114, 116 may be embedded underthe interconnect passivation layer 802, in some embodiments. The firstconductive wire 114 may be coupled to a first contact via 804 a and asecond contact via 804 b, in some embodiments. The second conductivewire 116 may be coupled to a third contact via 806 a and a fourthcontact via 806 b. Thus, during operation, a first current may beapplied across the first and second contact vias 804 a, 804 b to inducea first magnetic field in the first conductive wire 114, and a secondcurrent may be applied across the third and fourth contact vias 806 a,806 b to induce a second magnetic field in the second conductive wire116. The second magnetic structure 126 and the first magnetic structure(110 of FIG. 1A) may effectively concentrate the magnetic flux near thefirst and second conductive wires 114, 116.

FIG. 8B illustrates a cross-sectional view 800B of some embodiments ofthe inductor structure along line BB′ of FIG. 8A.

In some embodiments, the portions of the first and second conductivewires 114, 116 that are embedded in the interconnect passivation layer802 are not visible in the cross-sectional view 800B, as illustrated bythe dotted lines. In some embodiments, the interconnect passivationlayer 802 may comprise, for example, silicon dioxide, silicon nitride,polyimide compounds, or other suitable materials. Further, in someembodiments, contact layers 808 are below the second contact via 804 band the fourth contact via 806 b. Thus, in some embodiments, a portionof the first conductive wire 114 is embedded in the interconnectpassivation layer 802 and in electrical contact with one of the contactlayers 808 and the second contact via 804 b, and a portion of the secondconductive wire 116 is embedded in the interconnect passivation layer802 and in electrical contact with one of the contact layers 808 and thefourth contact via 806 b. In other embodiments, the second contact via804 b and the fourth contact via 806 b may be omitted. In someembodiments, the contact layers 808 may comprise, for example aluminum,copper, or the like. The contact layers 808 may be coupled to thesemiconductor devices 130 by the interconnect structure 140.

In some embodiments, isolation structures 812 may be embedded in thesubstrate 128 and between each of the semiconductor devices 130 forelectrical isolation between each semiconductor device 130. In someembodiments, the semiconductor devices 130 used to control the currentin the first and second conductive wires 114, 116 may be or comprise oneor more of the following: a low voltage (e.g., 1.8V-3.3V) device and ahigh voltage device.

FIGS. 9, 10, 11A-G, and 12-20 illustrate cross-sectional views 900,1000, 1100A-G, and 1200-2000 of some embodiments of a method of formingan inductor structure having a first pattern enhancement layer arrangedbetween a first magnetic structure and a first etch stop layer. AlthoughFIGS. 9, 10, 11A-G, and 12-20 are described in relation to a method, itwill be appreciated that the structures disclosed in FIGS. 9, 10, 11A-G,and 12-20 are not limited to such a method, but instead may stand aloneas structures independent of the method.

As shown in cross-sectional view 900 of FIG. 9 , in some embodiments, aninterconnect structure 140 may be formed over a substrate 128. Theinterconnect structure 140 may comprise interconnect wires 142 andinterconnect vias 144 embedded in an interconnect dielectric structure146. In some embodiments, the interconnect wires and vias 142, 144 maycomprise copper, tungsten, aluminum, or the like. The interconnectstructure 140 may be coupled to semiconductor devices 130 integrated onthe substrate 128. In some embodiments, the semiconductor devices 130may be or comprise metal oxide semiconductor field-effect transistors(MOSFETs). The MOSFETs comprise source/drain regions 130 a in thesubstrate 128. The semiconductor devices 130 may further comprise a gateelectrode 130 b arranged over a gate dielectric layer 130 c on thesubstrate 128.

In some embodiments, a first passivation layer 102 is formed over theinterconnect structure 140, and the first passivation layer 102 maycomprise, for example, a nitride (e.g., silicon nitride), an oxide(e.g., silicon dioxide), or the like. A first barrier layer 104 may beformed over the first passivation layer 102, and the first barrier layer104 may comprise, for example, silicon nitride, silicon carbide, or thelike. Thus, in some embodiments, the first barrier layer 104 maycomprise a same material as the first passivation layer 102. In otherembodiments, the first barrier layer 104 may comprise a differentmaterial than the first passivation layer 102. In some embodiments, thefirst passivation layer 102 and the first barrier layer 104 may bedeposited using a deposition process (e.g., chemical vapor deposition(CVD), physical vapor deposition (PVD), atomic layer deposition (ALD),etc.).

A first etch stop layer 106 is deposited over the first barrier layer104, and the first etch stop layer 106 may comprise, for example, ametal oxide, such as tantalum oxide, titanium oxide, another suitableetch stop material, or the like. In some embodiments, a method forforming the first etch stop layer 106 may include: forming a metalmaterial (e.g., tantalum) over the first barrier layer 104; andsubsequently performing a thermal annealing process (e.g., with water(H₂O)) to convert the metal material to a metal oxide.

A first pattern enhancement material 902 may be formed over the firstetch stop layer 106. The first pattern enhancement material 902 may forma layer having a first thickness t₁ in a range of between, for example,approximately 300 angstroms and approximately 1000 angstroms. A firstmagnetic structure 110 comprising a first group of layers 110 a, asecond group of layers 110 b, and a third group of layers 110 b may bedeposited over the first pattern enhancement material 902. The firstgroup of layers 110 a may comprise a tantalum material 904 depositedover the first pattern enhancement material 902, a cobalt zinc tantalum(CZT) material 906 deposited over the tantalum material 904, and anoxygen-CZT (OCZT) material 908 deposited over the CZT material 906. Insome embodiments, the tantalum material 904 comprises tantalum, the CZTmaterial 906 comprises CZT, and the OCZT material 908 comprises OCZT.

In some embodiments, the tantalum material 904 may form a layer having asecond thickness t₂ that is less than the first thickness t₁. Forexample, in some embodiments, the second thickness t₂ is in a range ofbetween approximately 15 angstroms and approximately 50 angstroms. Insome embodiments, the CZT material 906 may form a layer having a fourththickness t₄ that is in a range of between approximately 4000 angstromsand approximately 5000 angstroms. In some embodiments, the OCZT material908 may form a layer having a fifth thickness t₅ that is in a range ofbetween approximately 150 angstroms and approximately 500 angstroms. Inother embodiments, the fifth thickness t₅ may be greater than 500angstroms. Thus, the fourth thickness t₄ may be greater than the first,second, and fifth thickness t₁, t₂, t₅.

The amount of oxygen in the OCZT material 908 and/or the fifth thicknessis of the OCZT material 908 may influence the resistance of the firstmagnetic structure 110. In some embodiments, the first thickness t₁depends on the fifth thickness t₅. For example, if the fifth thicknessis of the OCZT material 908 is increased, the first thickness t₁ of thefirst pattern enhancement material 902 is also increased.

In some embodiments, the first pattern enhancement material 902comprises a material that can be dissolved by a same wet etchant that isused to remove portions of the tantalum material 904, the CZT material906, and the OCZT material 908. For example, in some embodiments the wetetchant used to pattern the first magnetic structure 110 is or comprisesa mixture of nitric acid and hydrofluoric acid. In such embodiments, thefirst pattern enhancement material 902 may comprise, for example,tantalum, silicon nitride, titanium, tungsten, zirconium, nickel,silicon germanium, tin, niobium, vanadium, or indium antimony. Further,in some embodiments, the first pattern enhancement material 902 maycomprise a material that has an oxygen concentration that does notexceed 10 percent. If the oxygen concentration of the first patternenhancement material 902 were to exceed 10 percent, in some embodiments,the oxygen in the first pattern enhancement material 902 would reactwith other elements when exposed to the wet etchant, and form oxideprecipitates.

Additionally, in some embodiments, the first pattern enhancementmaterial 902 comprises a material that has a higher etch rate than theOCZT material 908. In other embodiments, the first pattern enhancementmaterial 902 may have a faster or slower etch rate than one or more ofthe materials in the first magnetic structure 110. In some embodiments,the first pattern enhancement material 902, the tantalum material 904,the CZT material 906, and the OCZT material 908 may each be formed usinga deposition process (e.g., physical vapor deposition (PVD), chemicalvapor deposition (CVD), PE-CVD, atomic layer deposition (ALD),sputtering, etc.). Multiple cycles of deposition processes may berepeated for the tantalum material 904, the CZT material 906, and theOCZT material 908, depending on the number of groups of layers (e.g.,110 a, 110 b, 110 c, etc.) in the first magnetic structure 110.

As shown in cross-sectional view 1000 of FIG. 10 , a first masking layer1002 is formed over the first magnetic structure 110. In someembodiments, the first masking layer 1002 may comprise a photoresistmaterial and be formed using photolithography and removal (e.g.,etching) processes. The first masking layer 1002 may be arranged suchthat outer portions of the first magnetic structure 110 do not directlyunderlie the first masking layer 1002.

As shown in cross-sectional view 1100A of FIG. 11A, a first wet etchingprocess is performed to remove outer portions of the first magneticstructure 110 and of the first pattern enhancement material 902. Thecross-sectional views 1100A, 1100B, 1100C, 1100D, 1100E, 1100F, and1100G illustrate the first wet etching process respectively at first,second, third, fourth, fifth, sixth, and seventh times, where the secondtime is after the first time, the third time is after the second time,and so on.

The first wet etching process is illustrated by showing thecross-sectional view 1100A submerged in a wet etchant 1102. In someembodiments, the wet etchant 1102 used is a mixture of nitric acid andhydrofluoric acid, for example. During the first time, a topmost OCZTlayer 908 t is exposed to the wet etchant 1102, and first areas 1104 ofa topmost CZT layer 906 t are exposed.

As shown in the cross-sectional view 1100B of FIG. 11B, as the firstareas (1104 of FIG. 11A) of the topmost CZT layer 906 t are exposed, thewet etchant 1102 quickly removes portions of the topmost CZT layer 906 tand a topmost tantalum layer 904 t because the CZT material 906 and thetantalum material 904 have higher etching rates than the OCZT material908 when exposed to the wet etchant 1102. The topmost CZT layer 906 tand the topmost tantalum layer 904 t are removed so much faster than thetopmost OCZT layer 908 t, that OCZT residue 1106 is “free-floating” inthe wet etchant 1102; in other words, the OCZT residue 1106 isdiscontinuous with the topmost OCZT layer 908 t, and the OCZT residue1106 is completely surrounded by the wet etchant 1102. Thus, the OCZTresidue 1106 may be suspended or begin to “sink” (e.g., travel in adirection towards the first pattern enhancement material 902, forexample). The OCZT residue 1106 may exhibit random shapes in someembodiments, or in other words, are not common geometrical shapes suchas, for example, a circle, a triangle, a rectangle, etc. In someembodiments, the OCZT residue 1106 may be detected as CoO precipitates,for example, during chemical analysis, such as, EDX analysis. In otherembodiments, chemical analysis such as EDX analysis, for example, maydetect oxygen, cobalt, zinc, and tantalum when analyzing OCZT residue1106.

As shown in the cross-sectional view 1100C of FIG. 11C, the OCZT residue1106 begins to sink towards an intermediate OCZT layer 908 i as theintermediate OCZT layer 908 i is exposed to the wet etchant 1102. Theintermediate OCZT layer 908 i is etched away and second areas 1108 of anintermediate CZT layer 906 i are exposed to the wet etchant 1102.

Further, the OCZT residue 1106 is partially or completely removed by thewet etchant 1102 as the intermediate OCZT layer 908 i is exposed to thewet etchant 1102. As the OCZT residue 1106 from the topmost OCZT layer908 t is removed, OCZT residue 1106 from the intermediate OCZT layer 908i begins to form. It will be appreciated that the topmost OCZT layer 908t, the topmost CZT layer 906 t, and the topmost tantalum layer 904 tcontinue to be etched (e.g., removed) by the wet etchant 1102, and thus,the topmost OCZT layer 908 t, the topmost CZT layer 906 t, and thetopmost tantalum layer 904 t are narrower in the cross-sectional view1100C of FIG. 11C than in the cross-sectional view 1100B of FIG. 11B.

As shown in the cross-sectional view 1100D of FIG. 11D, as the secondareas (1108 of FIG. 11C) of the intermediate CZT layer 906 i areexposed, the wet etchant 1102 quickly removes portions of theintermediate CZT layer 906 i and an intermediate tantalum layer 904 ibecause the CZT material 906 and the tantalum material 904 have higheretching rates than the OCZT material 908 when exposed to the wet etchant1102. More OCZT residue 1106 from the intermediate OCZT layer 908 i maybe left “free-floating” in the wet etchant 1102 and other previouslyformed OCZT residue 1106 from the topmost OCZT layer 908 t may bepartially or completely removed.

As shown in the cross-sectional view 1100E of FIG. 11E, a bottommostOCZT layer 908 b, a bottommost CZT layer 906 b, and a bottommosttantalum layer 904 b are exposed to the wet etchant 1102, and more OCZTresidue 1106 may be produced from the bottommost CZT layer 906 b. Someof the OCZT residue 1106 may sink and contact the first patternenhancement material 902, as the first pattern enhancement material 902is exposed to the wet etchant 1102. The OCZT residue 1106 from thetopmost OCZT layer 908 t and the intermediate OCZT layer 908 i may bealmost or completely removed.

As shown in the cross-sectional view 1100F of FIG. 11F, portions of thefirst pattern enhancement material 902 begin to be removed by the wetetchant 1102 as the first magnetic structure 110 continues to be exposedand etched by the wet etchant 1102. The wet etchant 1102 also continuesto remove the OCZT residue 1106 before the first etch stop layer 106 isexposed. Thus, the first pattern enhancement material 902 gives the wetetching process more time to remove the OCZT residue 1106 before thefirst etch stop layer 106 is exposed. If the first etch stop layer 106were exposed before the OCZT residue 1106 was removed, the OCZT residue1106 would contact and stick to the first etch stop layer 106,negatively impacting the device performance. Increasing the thickness ofthe first pattern enhancement material 902 and/or choosing a materialfor the first pattern enhancement material 902 with a slower etch rateincreases the time for OCZT residue 1106 removal during the first wetetching process.

The cross-sectional view 1100G of FIG. 11G may show the first magneticstructure 110 after the first wet etching process is complete. The firstmagnetic structure 110 comprises layers of a tantalum layer 162, a CZTlayer 164, and an OCZT layer 166. A first pattern enhancement layer 108may be arranged between the first etch stop layer 106 and a lowermostone of the tantalum layer 162. Depending on the etching rate and/or onthe etching time of the first wet etching process, the first patternenhancement layer 108 may be wider than, narrower than, or about equalto a lowermost one of the tantalum layer 162. In some embodiments, thefirst magnetic structure 110 may have outermost sidewalls that arecurved.

In some embodiments, because the first wet etching process comprises thewet etchant 1102, the first magnetic structure 110 and the first patternenhancement layer 108 will be removed in lateral and verticaldirections, and at least a topmost layer 110 t of the first magneticstructure 110 may be narrower than the first masking layer 1002. Afterthe first wet etching process, in some embodiments, the first magneticstructure 110 and the first pattern enhancement layer 108 may completelyand directly underlie the first masking layer 1002. Further, the firstetch stop layer 106 may be resistant to removal by the wet etchant 1102(e.g., nitric acid and hydrofluoric acid), thereby protecting theunderlying layers of the inductor structure (e.g., first passivationlayer 102 of FIG. 9 , first barrier layer 104 of FIG. 9 , etc.). Afterthe first wet etching process, the wet etchant 1102 and the firstmasking layer 1002 are removed. The first pattern enhancement layer 108significantly mitigates OCZT residue (1106 of FIG. 11F) on the firstetch stop layer 106. Thus, if chemical analysis (e.g., EDX analysis)were to be conducted on the first etch stop layer 106 after the firstwet etching process, in some embodiments, OCZT residue (1106 of FIG.11F), such as CoO precipitates, may not be detected.

As shown in the cross-sectional view 1200 of FIG. 12 , a second etchingprocess may be performed to remove outer portions of the first etch stoplayer 106. A second masking layer (not shown) may be formed over thefirst magnetic structure 110 and/or the first etch stop layer 106, andthe second etching process may be performed according to the secondmasking layer. The second etching process may be a dry etching processin a substantially vertical direction.

In other embodiments (not shown), the second etching process may beomitted, such that the method continues from FIG. 11G to FIG. 13 ,thereby skipping FIG. 12 .

As shown in cross-sectional view 1300 of FIG. 13 , a first conductivewire 114 and a second conductive wire 116 may be formed over the firstmagnetic structure 110. In some embodiments, the first conductive wire114 and the second conductive wire 116 are laterally spaced apart fromone another. A second barrier layer 112 and a seed layer 1202 mayseparate each of the first and second conductive wires 114, 116 from thefirst magnetic structure 110. In some embodiments, the second barrierlayer 112 may, for example, comprise a dielectric material, such assilicon dioxide, silicon nitride, a low-k dielectric, or some othersuitable dielectric material. The second barrier layer 112 may, forexample, be deposited or grown by CVD, PVD, ALD, or some otherdeposition or growth process. In some embodiments, the seed layer 1202may be formed over the second barrier layer 112. The seed layer 1202 maycomprise copper, aluminum, gold, silver, alloy(s) of the foregoing, orother suitable materials. The seed layer 1202 may, for example, bedeposited or grown by CVD, PVD, sputtering, electrochemical plating,electroless plating, or some other deposition or growth process. Thefirst and second conductive wires 114, 116 may then be formed over anddirectly contact the seed layer 1202. The first and second conductivewires 114, 116 may, for example, each comprise copper, aluminum, gold,silver, alloy(s) of the foregoing, or any other suitable conductivematerial. The first and second conductive wires 114, 116 may, forexample, be deposited or grown by CVD, PVD, sputtering, electrochemicalplating (ECP), electroless plating, or some other deposition or growthprocess. In some embodiments, the second barrier layer 112, the seedlayer 1202, and/or the first and second conductive wires 114, 116 may begrown or deposited in a patterned photoresist layer, for example, andthe patterned photoresist layer may be subsequently removed after suchdeposition or growth processes.

As shown in cross-sectional view 1400 of FIG. 14 , a dielectricstructure 118 may be deposited over the first magnetic structure 110 andover the first and second conductive wires 114, 116. The dielectricstructure 118 is configured to electrically isolate the first and secondconductive wires 114, 116 from one another and may comprise, forexample, a polyimide compound, a polybenzoxazole compound, or any othersuitable dielectric material.

In some embodiments, the dielectric structure 118 may be depositedand/or grown by CVD, PVD, ALD, or another suitable deposition process.In some embodiments, the dielectric structure 118 may be formed by acuring process or a patterning and removal (e.g., etching) process, forexample. In some embodiments, the dielectric structure 118 may have adome-like upper surface. In other embodiments, the dielectric structuremay have a substantially flat upper surface by the patterning process(e.g., an etching process) and/or by a planarization process (e.g., achemical mechanical planarization process). In yet other embodiments,the dielectric structure may have a center portion that is recessedbelow topmost portions. The center portion is between the first andsecond conductive wires 114, 116.

As shown in cross-sectional view 1500 of FIG. 15 , a first isolationlayer 120 may be formed over the dielectric structure 118. The firstisolation layer 120 may, for example, comprise a nitride, siliconnitride, or another suitable dielectric material, and the firstisolation layer 120 may be deposited and/or grown by CVD, PVD, ALD, oranother suitable deposition process.

As shown in cross-sectional view 1600 of FIG. 16 , a third barrier layer122 may be formed to overlie the first isolation layer 120 and laterallysurround the first magnetic structure 110 and the first patternenhancement layer 108. The third barrier layer 122 may comprise, forexample, silicon nitride, silicon carbide, or the like. In someembodiments, the third barrier layer 122 may be deposited and/or grownby CVD, PVD, ALD, or another suitable deposition process.

As shown in cross-sectional view 1700 of FIG. 17 , a second etch stoplayer 124 may be formed over the third barrier layer 122, the firstetching stop layer 106, and the first barrier layer 104. In someembodiments, the second etch stop layer 124 may comprise a same materialand/or be formed using a same process as the first etch stop layer 106.

As shown in cross-sectional view 1800 of FIG. 18 , in some embodiments,a second pattern enhancement material 1802 may be formed conformallyover the second etch stop layer 124. The second pattern enhancementmaterial 1802 may comprise a same or different material than the firstpattern enhancement layer 108. In other embodiments, it will beappreciated that the second pattern enhancement material 1802 may beomitted, and that the method may continue from FIG. 17 to FIG. 19 ,thereby skipping FIG. 18 .

As shown in cross-sectional view 1900 of FIG. 19 , in some embodiments,a second magnetic structure 126 may be formed over the second etch stoplayer 124, and in some embodiments, over the second pattern enhancementmaterial 1802. In some embodiments, the second magnetic structure 126comprises a different structure than the first magnetic structure 110.For example, in some embodiments, the second magnetic structure 126 maynot comprise oxygen cobalt zinc tantalum. In such embodiments, thesecond pattern enhancement material 1802 may be omitted. In otherembodiments, the second magnetic structure 126 may comprise a samestructure as the first magnetic structure 110. In such otherembodiments, the second pattern enhancement material 1802 may be presentto remove residue formed during patterning of the second magneticstructure 126. In some embodiments, the second pattern enhancementmaterial 1802 and the second magnetic structure 126 may be removed by asame etchant.

As shown in the cross-sectional view 2000 of FIG. 20 , in someembodiments, the second magnetic structure 126 may undergo a third wetetching process to remove outer portions of the second magneticstructure 126. In some embodiments, where during the third wet etchingprocess, outer portions of the second pattern enhancement material (1802of FIG. 19 ) may be removed thereby forming a second pattern enhancementlayer 508 between the second etch stop layer 124 and the second magneticstructure 126. In such embodiments, the second pattern enhancement layer508 may allow the third wet etching process to have more space and moretime to remove any residue produced by the second magnetic structure 126during the third wet etching process. In other embodiments, residue isnot a side-effect of the third wet etching process, and thus, the secondpattern enhancement layer 508 may be omitted. Further, in someembodiments, the third wet etching process may be followed by a fourthetching process to remove outer portions of the second etch stop layer124.

It will be appreciated that prevention of residue formation on thesecond etch stop layer 124 by the second pattern enhancement layer 508during the third wet etching process may involve a similar mechanism asdepicted in FIGS. 11A-11G with respect to the prevention of OCZT residue(1106 of FIG. 11B) on the first etch stop layer 106 by the first patternenhancement layer 108 during the first wet etching process.

Nevertheless, due to the first and/or second pattern enhancement layers108, 508, residue (e.g., OCZT residue 1106 of FIG. 11F) between layersof the inductor structure may be mitigated such that the first andsecond magnetic structures 110, 126 reliably surround the first andsecond conductive wires 114, 116.

FIG. 21 illustrates a flow diagram of some embodiments of a method 2100of forming inductor structure having a first pattern enhancement layerarranged between a first magnetic structure and a first etch stop layer.

While method 2100 is illustrated and described below as a series of actsor events, it will be appreciated that the illustrated ordering of suchacts or events are not to be interpreted in a limiting sense. Forexample, some acts may occur in different orders and/or concurrentlywith other acts or events apart from those illustrated and/or describedherein. In addition, not all illustrated acts may be required toimplement one or more aspects or embodiments of the description herein.Further, one or more of the acts depicted herein may be carried out inone or more separate acts and/or phases.

At act 2102, a first pattern enhancement layer is formed over a firstetch stop layer.

At act 2104, a first magnetic structure is formed over the first patternenhancement layer. FIG. 9 illustrates a cross-sectional view 900 of someembodiments corresponding to acts 2102 and 2104.

At act 2106, a masking layer is formed over the first magneticstructure. FIG. 10 illustrates a cross-sectional view 1000 of someembodiments corresponding to act 2106.

At act 2108, a first etching process is performed to remove peripheralportions of the first magnetic structure and the first patternenhancement layer. FIGS. 11A and 8G illustrate cross-sectional views1100A and 1100B, respectively, of some embodiments corresponding to act2108.

At act 2110, a second etching process is performed to remove outerportions of the first etch stop layer. FIG. 12 illustratescross-sectional view 1200 of some embodiments corresponding to act 2110.

At act 2112, a first conductive wire and a second conductive wire areformed over the first magnetic structure. FIG. 13 illustratescross-sectional view 1300 of some embodiments corresponding to act 2112.

At act 2114, a dielectric structure is deposited over the first andsecond conductive wires, wherein the dielectric structure separates thefirst conductive wire from the second conductive wire and covers thefirst and second conductive wires. FIG. 14 illustrates cross-sectionalview 1400 of some embodiments corresponding to act 2114.

At act 2116, a second etch stop layer is formed over the dielectricstructure. FIG. 17 illustrates cross-sectional view 1700 of someembodiments corresponding to act 2116.

At act 2118, a second magnetic structure is formed over the second etchstop layer. FIG. 19 illustrates cross-sectional view 1900 of someembodiments corresponding to act 2118.

Therefore, the present disclosure relates to a new method ofmanufacturing an inductor structure having a first pattern enhancementlayer arranged between a first magnetic structure and a first etch stoplayer to mitigate the presence of residue upon patterning the firstmagnetic structure.

Accordingly, in some embodiments, the present disclosure relates to aninductor structure, comprising: an etch stop layer arranged over aninterconnect structure overlying a substrate; a magnetic structurecomprising a plurality of stacked layers arranged over the etch stoplayer, the magnetic structure comprising a bottommost layer that iswider than a topmost layer; a first conductive wire and a secondconductive wire extending in parallel over the magnetic structure,wherein the magnetic structure is configured to modify magnetic fieldgenerated by the first conductive wire and the second conductive wire;and a pattern enhancement layer arranged between the bottommost layer ofthe magnetic structure and the etch stop layer, wherein the patternenhancement layer has a first thickness, and wherein the bottommostlayer of the magnetic structure has a second thickness less than thefirst thickness.

In other embodiments, the present disclosure relates to an inductorstructure, comprising: an interconnect structure disposed over asemiconductor substrate; a first etch stop layer arranged over theinterconnect structure; a first magnetic structure arranged over thefirst etch stop layer, the first magnetic structure comprising a cobaltzinc tantalum (CZT) layer between a lowermost tantalum layer and atopmost oxygen-CZT layer; one or more conductive wires disposed over thefirst magnetic structure and defining an inductor; and a patternenhancement layer arranged between the lowermost tantalum layer and thefirst etch stop layer.

In yet other embodiments, the present disclosure relates to a method offorming an inductor structure, comprising: forming a first patternenhancement layer over a first etch stop layer; forming a magneticstructure over the first pattern enhancement layer, wherein the magneticstructure comprises layers of oxygen cobalt zinc tantalum (OCZT)material, layers of tantalum material, and layers of cobalt zinctantalum (CZT) material, wherein the first pattern enhancement layerdirectly contacts one of the layers of tantalum material; and performinga first etching process to remove peripheral portions of the magneticstructure and the first pattern enhancement layer, wherein the magneticstructure and the first pattern enhancement layer are etched by a sameetchant.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A method of forming an inductor structure,comprising: forming a first pattern enhancement layer over a first etchstop layer; forming a magnetic structure over the first patternenhancement layer, wherein the magnetic structure comprises layers ofoxygen cobalt zinc tantalum (OCZT) material, layers of tantalummaterial, and layers of cobalt zinc tantalum (CZT) material, wherein thefirst pattern enhancement layer directly contacts one of the layers oftantalum material; and removing peripheral portions of the magneticstructure and the first pattern enhancement layer, wherein the magneticstructure and the first pattern enhancement layer are etched by a sameetchant in a first etching process.
 2. The method of claim 1, whereinduring a first time of the first etching process, the first patternenhancement layer completely covers the first etch stop layer, andcobalt oxygen precipitates are surrounded by a wet etchant of the firstetching process; wherein during a second time of the first etchingprocess, the wet etchant removes the cobalt oxygen precipitates; andwherein during a third time of the first etching process, the wetetchant removes the first pattern enhancement layer from portions of thefirst etch stop layer.
 3. The method of claim 1, wherein the sameetchant of the first etching process is a wet etchant, and wherein thewet etchant comprises a mixture of nitric acid and hydrofluoric acid. 4.The method of claim 1, further comprising: forming a first conductivewire and a second conductive wire over the magnetic structure, whereinthe first and second conductive wires are laterally spaced apart fromone another; depositing a dielectric material over the first and secondconductive wires, wherein the dielectric material completely covers topsurfaces of the first and second conductive wires; forming a second etchstop layer over the dielectric material; and forming an additionalmagnetic structure over the second etch stop layer.
 5. The method ofclaim 4, wherein after forming the second etch stop layer and beforeforming the additional magnetic structure, the method further comprises:forming a second pattern enhancement layer over the second etch stoplayer.
 6. The method of claim 4, further comprising: forming aninterconnect structure disposed over a semiconductor substrate, whereinthe interconnect structure comprises an alternating stack of wires andvias, and wherein the first etch stop layer overlies a top of theinterconnect structure.
 7. The method of claim 1, further comprising:removing peripheral portions of the first etch stop layer, wherein theremoving of the peripheral portions of the first etch stop layercomprises a second etching process, and wherein the first and secondetching processes are respectively a wet etching process and a dryetching process.
 8. A method of forming an inductor structure,comprising: forming an interconnect structure overlying a substrate;depositing a first etch stop layer (ESL) overlying the interconnectstructure; depositing a first pattern enhancement layer overlying thefirst etch stop layer; repeatedly depositing a first magnetic layeroverlying the first pattern enhancement layer to form a first magneticstructure comprising multiple instances of the first magnetic layer,wherein the first magnetic layer comprises a first layer, a second layeroverlying the first layer, and a third layer overlying the second layer,and wherein the first, second, and third layers comprise metal;performing a first wet etch into the first magnetic structure and thefirst pattern enhancement layer until the first ESL is exposed, whereinthe first wet etch has a lower etch rate for the third layer relative tothe first and second layers; forming a first wire and a second wireoverlying the first magnetic structure; depositing a second ESLoverlying the first wire and the second wire; and repeatedly depositinga second magnetic layer overlying the second ESL to form a secondmagnetic structure comprising multiple instances of the second magneticlayer, wherein the second magnetic layer comprises a fourth layer, afifth layer overlying the fourth layer, and a sixth layer overlying thefifth layer, and wherein the fourth, fifth, and sixth layers comprisemetal.
 9. The method of claim 8, further comprising: depositing a secondpattern enhancement layer overlying the second ESL, wherein the secondmagnetic layer is repeatedly deposited overlying the second patternenhancement layer to form the second magnetic structure; and performinga second wet etch into the second magnetic structure and the secondpattern enhancement layer until the second ESL is exposed, wherein thesecond wet etch has a lower etch rate for the sixth layer relative tothe fourth and fifth layers.
 10. The method of claim 8, wherein thefirst wet etch etches the first magnetic structure and the first patternenhancement layer using an etchant comprising a mixture of nitric acidand hydrofluoric acid.
 11. The method of claim 8, wherein the firstmagnetic layer consists essentially of the first, second, and thirdlayers, and wherein the second magnetic layer consists essentially ofthe fourth, fifth, and sixth layers.
 12. The method of claim 8, whereinthe first, second, and third layers have the same material compositionas the fourth, fifth, and sixth layers.
 13. The method of claim 8,further comprising: performing a first dry etch into the first ESL afterthe first wet etch completes, wherein the first pattern enhancementlayer directly contacts the first ESL and the first layer.
 14. A methodof forming an inductor structure, comprising: depositing a first etchstop layer (ESL) overlying a substrate; depositing a first patternenhancement layer overlying the first etch stop layer; repeatedlydepositing a first magnetic layer overlying the first patternenhancement layer to form a first magnetic structure comprising multipleinstances of the first magnetic layer, wherein the first magnetic layercomprises a first layer, a second layer overlying the first layer, and athird layer overlying the second layer, and wherein the first, second,and third layers comprise metal; performing a first wet etch into thefirst magnetic structure and the first pattern enhancement layer untilthe first ESL is exposed; and forming a first wire and a second wireoverlying the first magnetic structure; wherein during the first wetetch, a wet etchant of the first wet etch etches the first and secondlayers at a faster rate than the third layer so as to undercut the thirdlayer, undercut portions of the third layer break off of a bulk of thethird layer and migrate to the first pattern enhancement layer, and thewet etchant removes the undercut portions at the first patternenhancement layer before etching completely through the first patternenhancement layer.
 15. The method of claim 14, further comprising:depositing a second ESL overlying the first wire and the second wire;and repeatedly depositing a second magnetic layer overlying the secondESL to form a second magnetic structure comprising multiple instances ofthe second magnetic layer, wherein the second magnetic layer comprises afourth layer, a fifth layer overlying the fourth layer, and a sixthlayer overlying the fifth layer, and wherein the fourth, fifth, andsixth layers comprise metal.
 16. The method of claim 15, furthercomprising: depositing a second pattern enhancement layer overlying thesecond ESL, wherein the second magnetic layer is repeatedly depositedover the second pattern enhancement layer to form the second magneticstructure; and performing a second wet etch into the second magneticstructure and the second pattern enhancement layer until the second ESLis exposed.
 17. The method of claim 15, further comprising: forming adielectric structure covering and laterally surrounding the first andsecond wires, wherein the second magnetic layer is repeatedly depositedover the dielectric structure to form the second magnetic structure. 18.The method of claim 14, wherein the second and third layers comprisecobalt zinc tantalum (CZT), and wherein the third layer has an elevatedconcentration of oxygen relative to the second layer.
 19. The method ofclaim 18, wherein the third layer directly contacts the second layer.20. The method of claim 14, further comprising: performing a first dryetch into the first ESL after the first wet etch to remove peripheralportions of the first ESL.